Shell posh fuel is around 7p more a litre here, a tank is 60 litres so £4.20p per fill up or £42 for ten fill ups. I'm actually more convinced by Millers than I am by BP and Shell's claims. For no real reason. Pretty scientific huh?!

TMP - no warranty left on mine (and 100% owned) so I can do what the hell I want with it!

I want to try this millers additive but not sure which one to use??

Ive seen two online...can someone let me know which one I should try for my E90 320d?

DON'T use Millers Sport 4 - it will be fine for your car, but this is now obsolete, and it does degrade over time (it says so on the bottle). Hence it may be old stock.
The new type is Millers Ecomax, which is around the same price (£8-£9 per 500ml bottle). This, at normal dosage treats 500 litres of fuel, although Millers recommend double strength for the first dosed fill-up.

My experience with Sport 4 is that it did leave a black deposit in the exhaust tip - Millers specifically state that Sport 4 is OK for DPF's - but since using Ecomax, my tip has been clear. No other discernable difference apart from the bottle is a little more awkward to get the correct dose.

Wasn't Countdown, was it? That is often used more in the haulage sector.

The other point about the premium fuel costs per litre. I worked out that about 4-pence was the cut off for me, for making premium a 'no cost' increase choice. More than that and an additive makes more financial sense.

But that is for my driving conditions, where I do a lot of steady speed driving and I get an mpg gain. For those with driving conditions where there is no mpg gain, then the cheapest solution is obviously best, if it is for the engine cleaning properties, etc.

I'm pretty stop start, almost no motorway driving (there aren't any in Cornwall!), a small amount of dual carriagway but mostly fastish single lane A roads and twisty B roads - no idea what would suit me. Probably a small diesel Fiesta...

With the current Diesel Power Eco Max stuff in a 500ml bottle (what I use) you add 1ml per litre of fuel.

The bottle has a dosing cap that has 25ml and 50ml markings on it, to give a suitable dose for adding 25litres and 50 litres of fuel to the tank.

For the first usage or when re-filling the tank from nearly empty I add 75ml (50ml + 25ml in two doses). Thereafter if topping up with (say) a quarter of a tank left you just add 50ml to the tank before adding 50litres of fuel to mix it in.

A 500ml bottle adds 2p/litre to your fillup (a little more if you buy it off-the-shelf in Halfords) which is less than the 5p/6p a litre that Shell/BP typically charge for V-Power/Ultimate.

I've found that Millers works well with Sainsburys City Diesel in my car and I don't like buying Tesco/Asda/Morrisons diesel as they always seem to be the ones who have issues with fuel contamination from buying the cheapest crap they can find and ship to the UK.

IMO the best VFM fuel out there now is Shell Fuelsave judging by how efficiently my car runs on it and the difference in fuel consumption I've seen.

With the current Diesel Power Eco Max stuff in a 500ml bottle (what I use) you add 1ml per litre of fuel.

The bottle has a dosing cap that has 25ml and 50ml markings on it, to give a suitable dose for adding 25litres and 50 litres of fuel to the tank.

For the first usage or when re-filling the tank from nearly empty I add 75ml (50ml + 25ml in two doses). Thereafter if topping up with (say) a quarter of a tank left you just add 50ml to the tank before adding 50litres of fuel to mix it in.

A 500ml bottle adds 2p/litre to your fillup (a little more if you buy it off-the-shelf in Halfords) which is less than the 5p/6p a litre that Shell/BP typically charge for V-Power/Ultimate.

I've found that Millers works well with Sainsburys City Diesel in my car and I don't like buying Tesco/Asda/Morrisons diesel as they always seem to be the ones who have issues with fuel contamination from buying the cheapest crap they can find and ship to the UK.

IMO the best VFM fuel out there now is Shell Fuelsave judging by how efficiently my car runs on it and the difference in fuel consumption I've seen.

IMO the best VFM fuel out there now is Shell Fuelsave judging by how efficiently my car runs on it and the difference in fuel consumption I've seen.

I know others, including DieselCar magazine viewed the Shell Diesel Extra as the best VFM diesel. As I mentioned in another post that is the one I've found is as good as Ultimate in my car, but couldn't buy locally. Shell and commercial customers say about a 5% saving across their fleets. I say it's about that for my car, for the Shell Extra and Ultimate, above standard fuels.

As I noted earlier on, I'm not a big fan of Fuel Save. Car seems a bit lethargic. I had a similar lethargic experience with Tesco supermarket diesel.

I may give V Power a go some time but as I also said before, it is a gas-to-liquid fuel unlike other diesels and the energy content per litre is lower than ordinary diesel. It has a higher cetane rating so your car may feel smoother but in theory at least it will develop less power.

Back to the Marine diesels as they were mentioned earlier - they all run on red diesel which from what I understand is of a lesser quality than road pump diesel. Even now leisure boats have to pay tax on diesel it is still the red stuff as it comes from the same place the fishing/commercial diesel comes from. Most performance marine diesels are based on truck engines as far as I know. Additives are available for them but they are more aimed at emuslifying any water present in the tanks so it can be burned and killing the fuel bug...

Anyway back to cars, I used the cheapest fuel I can find currently Jet or Sainsburys round here (127.9p) plus millers. I have no idea if the millers makes any difference or not as I have not had the car long and only used one tank with no additive. I read some old threads on here that seemed to suggest it was worth using and works out cheaper than premium...

Driveability (midrange, part-throttle) is as good as BP Ultimate or Sainsbury's City Diesel + Millers. Low rpm, light throttle torque and throttle response is the best of any fuel I've tried and this allows you to drive economically.

Economy seems best of all. I've seen average mpg and range readings when using Fuelsave that I've not seen before with other fuels over many repetitions of the same journey under similar conditions. I live in Suffolk and do a regular commute to Reading/Newbury which is a 160/180 mile journey that allows the car to fully warm up and run efficiently.

Driveability (midrange, part-throttle) is as good as BP Ultimate or Sainsbury's City Diesel + Millers. Low rpm, light throttle torque and throttle response is the best of any fuel I've tried and this allows you to drive economically.

Economy seems best of all. I've seen average mpg and range readings when using Fuelsave that I've not seen before with other fuels over many repetitions of the same journey under similar conditions. I live in Suffolk and do a regular commute to Reading/Newbury which is a 160/180 mile journey that allows the car to fully warm up and run efficiently.

Good result. Much the way I see the 'improved' fuels, particularly mid range performance for cruising and over distance.

My nearest Shell FuelSave is 60 miles away, shame, as I'd love to try it. Particularly as I noticed today, our local BP station has Ultimate diesel @ 10-pence a litre above the standard fuel.

Looks as if I will need to move across to Millers, 10-pence is way too much, we were reasonable at a 4-pence difference.